#!/usr/bin/env bash

mv /etc/apt/sources.list /etc/apt/sources.list.bak
echo "deb https://mirrors.ustc.edu.cn/debian/ stretch main contrib non-free" >/etc/apt/sources.list
echo "deb https://mirrors.ustc.edu.cn/debian/ stretch-updates main contrib non-free" >>/etc/apt/sources.list
echo "deb https://mirrors.ustc.edu.cn/debian/ stretch-backports main contrib non-free" >>/etc/apt/sources.list
echo "deb https://mirrors.ustc.edu.cn/debian-security/ stretch/updates main contrib non-free" >>/etc/apt/sources.list